Centering for concrete floors.



N0. 804,237. PATENTBD NOV. 14, 1905. P. KI THNB.

GENTERING FOR CONCRETE FLOORS.

APPLICATION FILED MAR.17, 1905.

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UNITED A STATES PATENT OFFICE.

PAUL KIIHNE, OF NEW YORK, N. Y.

CENTERING FOR CONCRETE FLOORS.

Specification of Letters Patent.

Patented. Nov. 14, 1905.

Application filed March 17,1905. Serial No. 250.519-

. the beams and supported in position for easting the concrete body over the same and then removed with great facility without injury to the concrete floor; and for this purpose the invention consists in the novel features of construction, which will be fully described hereinafter and finally pointed out in the claims.

In the accompanying drawings, Figure l is a vertical transverse section through a concrete floor, showing my improved centering in position. Fig. 2 is a detail side elevation, drawn on a larger scale, of a screw-hanger for my improved centering for concrete floors.

Fig. 3 is a side elevation of said screw-hanger. Fig. 4 is a detail of the centering, showing the expansion-joint at the center of the same. Fig. 5 is a detail of an expansion-joint located at the corner of the centering, and Fig. 6 is a detail of an expansion-joint located at the center portion of the centering.

Similar letters of reference indicate corresponding parts throughout the several views.

Referring to the drawings, a denotes a screw-hanger for my improved centering for concrete floors. The screw-hanger consists of a U-shaped shackle of wrought-iron or other suitable material which is curved at the upper end and screw-threaded at the lower ends. The screw-nuts (Z, which are screwed on the lower ends of the shackle, serve for supporting a transverse plate (2, which is supported by nuts at the lower ends of the shackle, so as to support the cross-pieces c, on which the centering is supported. The upper curved end of each shackle is supported by a semicircular cast-metal block (Z which is provided with a circumferential groove for the shackle. The screw-hanger described is suspended from the base of the I-beanis I by meansof hook-shaped clamps f, the lower' ends of which are attached, by means of trans verse bolts 6 and nuts I), to the semicircular suspension-block at the upper part of the shackle, the space between the suspensionblock and the lower parts or shanks of the clamps being filled up by a number of ringshaped washers g, of which a larger or smaller number may be used, according to the size of the base of the I-beams. The screw-hangers a are applied to the base of the I-beams at a suitable distance from each other, supporting the cross-pieces braced to the shackle of the hanger. On the cross-pieces are placed boards 1 at both sides of the hanger parallel with the beams and eyebolts, on which are supported joists j, the inner faces of which are slightly inclined,so as to hold facing-boards 7i adjacent thereto in slightly-inclined position one at each side and at some distance from the I- beam. On the joists are again supported cross-pieces it, on which are placed the planks p, which complete the centering and which are placed at such a position above the main cross-pieces as required by the thickness of the concrete floor to be laid. Between the slightly-inclined side boards 7b and the center planks is interposed a bent plate 39', of sheet metal, that is attached to the inclined side boards and curved so as to overlap the edge planks of the center, forming thereby, with the edge planks, an expansion-joint that gives sufficiently when the setting of the concrete floor takes place, so as to prevent the uneven setting of the concrete floor, which was hitherto caused by the rigid construction of the centering and which sometimes exerted an injurious influence on the parts of the floor or columns supporting the same. A single expansion-joint may be formed in the planking in some instances, in which case the joint is arranged approximately in the center thereof, as shown in Figswt and 6. In order to prevent the adhesion of the cement to the planks and to the sheet metal, it is covered with a layer p of oiled paper, as shown in Figs. 5 and 6. hen the centering is placed in position between the beams, the concrete floor is tamped over the sameand into the space between the beams and the side boards up to the required height above the beams, being then properly leveled for laying the flooring on the same.

After the concrete floor has set the center,-'

ing is removed. This is accomplished by loosening the screws at the lower ends of the shackles, so as to gradually lower the crosspieces and the woodwork supported thereon. As the loosening of the screw-nuts and the lowering of the woodwork takes place slowly, the woodwork is gradually released from the concrete floor, which is thereby kept intact without cracking. Owing to the slight inclination of the side boards and the timbers supporting the same, the lowering of the woodwork takes place easily, so that the individual parts can be removed. Lastly, the clamps are removed from the base of the beams by breaking away the adjacent pieces convenient support of the woodwork and its removal after the concrete floors are laid, and that by the use of the expansion-joints the woodwork is permitted to expand without injury to the body of concrete formed on the same. c

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A centering for concrete floors, comprising in its construction screw-hangers suspended from the I-beams, said screw-hangers embodying shackles, cross-pieces supported in said shackles, and woodwork supported on said cross-pieces and provided with expansion-joints for permitting the expansion of the woodwork without injury to the concrete floor formed thereon.

2. A centering for concrete floors, co'nsist ing of screw-hangers embodying U-shaped shackles, guide-pieces supported at the upper ends of the shackles, bolts attached to said guide-pieces, cross-pieces supported by said shackles, and woodwork supported on said cross-pieces. I

3. A screw-hanger for the centering of concrete floors, comprising-a U-shaped shackle, a bottom plate supported on the lower ends of said shackle, a semicircular guide-plate supported at the upper part of the same, clamps applied to the hangers, bolts passing through the shanks of the clamps and the guide-piece of the shackle and washers interposed between said guide-piece and the shanks of the clamps.

4. A centering for concrete floors, consisting of screw-hangers applied to the beams, cross-pieces supported on said screw-hangers,

planks and joists supported on the cross-pieces,

inclined side boards adjacent the beams, transverse pieces supported on the joists, planks placed on said cross-pieces, and a sheet-metal expansion-joint formed between the inclined side boards and the edge planks, the sheet metal overlapping the edge planks.

In testimony that I claim the foregoing as my invention 1 have signed my name in presence of two subscribing witnesses.

PAUL KUHNE. 

